Connecting arrangement for cover, especially furnace covers



CONNECTING ARRANGEMENT FOR COVER, ESPECIALLY FURNACE COVERS Filed Jan. 29, 1965 2 Sheets-Sheet 1 .fm/enfon' Nov. 21, 1967 A. VO'GT 3,353,582

CONNECTING ARRANGEMENT FOR COVER, ESPECIALLY FURNACE COVERS Filed Jan. 29, 1965 4 2 Sheets-Sheet 2 INVENTOR.

Kfrea 14 BY United States Patent 0 4 Claims. (Cl. 1582) The present invention relates to a cover or door especially for furnaces, oil-fired boilers and the like. More specifically, the present invention concerns a cover which can be swung about its hinge away from an opening in a furnace or the like to be closed and sealed, said cover being so attached to the hinge that it can be displaced relative to the hinge pins in a direction perpendicular to the sealing surface of the cover and by clamping means can be pressed against a sealing surface surrounding said opening.

Heretofore known covers of the above mentioned type are primarily of the construction illustrated in FIG. 1 according to which a door 15 is arranged opposite an opening 1 in a frame 2 mounted for instance on a fire box of an oil-fired furnace. Door 15 has an opening 16 for receiving therein an oil burner (not shown). Door 15 is mounted on one side on a movable member, for instance a plate 8 which can pivot on a hinge pin 6. Plate 8 carries bolts 10 which extend through corresponding bores 18 in door 15 in a direction perpendicular to the sealing surface of the door. Plate 8, furthermore, has secured therein a clamping screw 12 which extends through a slot 20 in door 15 and is threadedly engaged by a clamping nut 14. Door 15 is retained in its closed position by a locking plate 7 pivotally arranged on a hinge pin and carrying bolts 9 which are received in bores 17 of door 15. Plate 7 has secured thereto a clamping screw 11 which in closed position of door 15 extends through a slot 19 therein and is in threaded engagement with a clamping nut 13.

Due to the inevitable variations in the tolerances, it is necessary to provide adequate clearance between bolts and the cooperating bores 18 in door 15. Consequently, when nut 13 is loosened or unscrewed to permit door to swing away from frame 2, door 15 will drop when the friction produced by the contact pressure of nut 14 between door 15 and plate 8 is overcome by the weight of the door including the burner carried thereby. In such an instance, it will then be necessary when desiring to close the door, to lift the door with the burner. This is, of course, frequently very difiicult when a heavy door for a large boiler is involved.

" It is, therefore, an object of the present invention to provide a cover or door of the above mentioned general type, which will overcome the drawbacks outlined above.

It is another object of this invention to provide a cover or door as set forth above, whose end to be opened will not drop relative to the hinged end when the cover or door is being opened.

It is still another object of this invention to provide a cover or door as set forth in the preceding paragraph, in which any manufacturing tolerances between the diameter of the bolt means secured to the hinge member of the cover with regard to the cover openings receiving said bolt means will not affect an easy opening and closing of the cover.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

FIG. 1 illustrates a cover or door arrangement as heretofore used in connection with the opening of a fire box;

FIG. 2 shows partly in section and partly in view a door bolt connection according to the present invention; FIG. 3 is a section through the dot-dash line encircled portion of the door shown in FIG. 1, but equipped withmeans according to the invention for preventing the escape of gases from a furnace opening or the like to be closed by the cover or door according to the invention.

As mentioned above, the present invention concerns a hinged cover or door, especially for furnaces and the fire box of oil-fired boilers, in which the door is supported on a movable member which latter is hinged to a frame adjacent the furnace opening to be closed by the cover. The present invention more specifically concerns the connection of that cover or door portion which is connected to the hinge member. More specifically, the present invention is characterized primarily in that the hinge member connected to the cover or door has secured therein bolt means which extend into openings of the adjacent cover or door end portion but do so in spaced relationship to the adjacent wall surface of said openings, while two tapered sleeves or bushings interposed between the inner wall surfaces of said openings and said bolts means are adapted to be adjusted relative to each other in such a way as firmly to clamp-connect said cover or door to said bolt means. A nut threadedly engages one of said bushings and is adapted to bear upon the other bushing so as to bring about a relative adjustment of said bushings toward each other.

Referring now to FIG. 2, this figure shows a door supporting bolt connection according to the present invention. More specifically, the pivotable member adapted to be hingedly connected to a frame is designated with the reference numeral 8' and represents a member which functionally corresponds to the member 8 of FIG. 1. The door or cover in FIG. 2 is designated with the reference numeral 15. Bolt 30, which .is connected to or forms a part of hingeplate 8 and functionally corresponds to bolt 10 of FIG. 1, extends into a large bore 31 of door 15. As will be seen from FIG. 2, the outer diameter of bolt 30 is considerably less than the diameter of bore 31 so that an annular space is provided between each bolt 30 and the respective hole or bore 31 pertaining thereto. Interposed between each bolt 30 and the wall surface of bore 31 pertaining thereto are two nested sleeves or bushings 32, 33. Inner bushing 32 has its outer end provided with a threaded section 34, while the inner surface of bushing 32 is cylindrical and fits guiding bolt 30. Sleeve 32 furthermore has a tapered outer surface 32a which tapers in the direction toward the threaded portion 34 and engages a correspondingly tapered inner surface 33a of outer sleeve 33. Outer sleeve 33 is provided with a cylindrical outer surface 33b for engagement with the cylindrical bore 31.

As will be seen from FIG. 2, sleeve 32 has a reduced diameter section 32b between the threaded portion 34 and the tapered portion 32a. Sleeve 32 is provided with a plurality, for instance three longitudinal slots 36 uniformly circumferentially spaced from each other and extending into the area of the reduced diameter section 32b. It will be evident that in this way bushing 32 is divided into a plurality of resilient segments. Outer bushing 33 is provided with three similar longitudinal slots 39, for instance three siots spaced from each other -by and extending from the lower end of bushing 33 nearly to its upper end which is provided with a flange and is adapted to be engaged by a nut 35 in threaded engagement with the threaded section 34 of inner sleeve 32.

From the above, it will be evident that when nut 35 is tightened, outer bushing 33 is displaced relative to inner bushing 32. As a result thereof, a wedging action is exerted upon bushings 32 and 33, and the segments of inner bushing 32 are firmly pressed against bolt 30 while the segments of outer bushing 33 are tightly pressed against the wall of bore 31. Consequently, bolt 30 and door 15' are thus firmly wedge-clamped together so that door 15' and hinge plate 8 form a firmly interconnected rigid entirety which is adapted to pivot about pin 6 (see FIG. 1) without any tendency of door 15' to drop or tilt when the door is being opened.

It is not necessary to mount bushings similar to those disclosed in connection with the FIG. 2 arrangement on that side of the door which is to swing away from the 'frame. However, if for some reason a kind of outer symmetrical appearance is desired, the bolts 9 of FIG. 1 may be somewhat lengthened to receive caps similar in outer appearance to nut 35 of FIG. 2. If it is desired to employ the bolt-door connection with doors which, in- Stead of opening toward the left with regard to FIG. 1, open toward the right of FIG. 1, it is, of course, merely necessary to employ the bolt-door connection of FIG. 2 to the hinge member 7 of FIG. 1 instead of to the hinge member 8.

If it is desired to have door 15' arranged more closely to the sealing surface or to withdraw it therefrom at the hinge side, it is merely necessary to unscrew nuts 35 to such an extent that bushings 32 and 33 can be displaced relative to each other, to shift the door to the desired new position, and then to re-tighten the nuts 35. From the above, it will be evident that the present invention will prevent tilting of door 15 when it is being opened, even if the door carries a heavy burner, and notwithstanding the short length of bores 31.

In order to prevent inner bushing 32 or bushings 32,33 from rotating when nut 35 is tightened, bolt 30 may be provided wiht a laterally projecting pin 38 which extends into a recess 37 provided in the inner bushing 32.

Referring now to FIG. 3, the latter illustrates a section through the upper dot-dash line encircled portion of the furnace door of FIG. 1 but with safety means according to the present invention. More specifically door 15" carries a pipe 24 which extends through and, for instance, is press-fitted in a bore 23 in the door. The outer end of pipe 24 is connected to an oil burner 40 with a blower 42 therein, while the burner pipe 41 extends through the opening 16 in door 15". The burner 40 with its pipe 41 is connected to the door 15" by means of a flange 43 and bolts 44. In two annular grooves 21 on the inner face of door 15" there are provided two spaced concentric packing rings 22. These rings can be fitted without difficulty because the door is displaceable on the guiding bolts in a direction perpendicular to the sealing surface of the fire box opening, and such displacement permits a plurality of seals to be pressed uniformly against the sealing surface.

Pipe 24 terminates betweent he packing rings 22. Consequently, when door 15" is closed, an annular cavity is formed between the packing rings 22, and in this annular cavity there is by the burner blower maintained an air pressure which is always higher than the pressure in the fire box. Therefore, even if a leak should occur in the course of time at one of the two seals, no combustion gases can emerge from the furnace but at best blower air. This sealing or safety arrangement is, therefore, particularly advantageous for heating boilers in which a subatmospheric pressure prevails in the fire box and in which, therefore, there exists an increased danger of harmful gases escaping and poisoning or contaminating the adjacent air. The arrangement of FIG. 3 assures a satisfactory sealing of the fire box, particularly with high pressure boilers.

It is, of course, to be understood that the present invention is, by no means, limited to the particular arrangements shown in the drawing but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. In combination with a cover, especially furnace door: a supporting member provided with means for hingedly connecting said supporting member to a frame, bolt means secured to said supporting member and having a substantially cylindrical peripheral surface, said cover having one end portion thereof provided with passage means of substantially circular cross section, said bolt means extending into said passage means but having a diameter considerably less than the diameter of said passage means so as to confine an annularspace with the surface of said passage means, two coaxially arranged slotted bushings arranged within said annular space and respectively having those peripheral wall surfaces thereof which face each other provided with substantially the same but inversely arranged taper and slidably engaging each other along said taper, said bushings having those peripheral surfaces thereof which face away from each other designed as cylindrical surfaces, the inner one of said two bushings having its inner peripheral surface in engagement with the cylindrical surface of said bolt means, and means arranged at that end of said inner bushing which is remote from said supporting member and operable to engage and move said outer bushing relative to said inner bushing so as to cause said outer bushing to engage and clamp-connect said cover to said bolt means.

2. In combination with a cover, especially furnace door: a supporting member provided with means for hingedly connecting said supporting member to a frame, bolt means secured to said supporting member, said cover having one end portion thereof provided with passage means receiving and surrounding said bolt means in spaced relationship thereto, first slotted bushing means interposed between said bolt means and the adjacent wall surface of said passage means, said first bushing means having its inner surface in engagement with the adjacent peripheral surface of said bolt means and having its outer peripheral surface of that end portion thereof which is adjacent said supporting member provided with a taper tapering in the direction toward the other end portion of said first bushing means, the outer peripheral surface of said other end portion being provided with a thread, second slotted bushing means interposed between said first bushing means and the adjacent wall surface of said passage means and having its inner surface tapering in-conformity with and engaging the tapering surface of said first bushing means, and means threadedly engaging said thread of said first bushing means and being operable to engage and move said second bushing means relative to said first bushing means in the direction toward said supporting member to thereby cause said second bushing means to engage and wedge-clamp said cover and said bolt means together.

3. An arrangement according to claim 2, in which said first bushing means is provided adjacent said supporting member with recess means, and which includes pin'means arranged in said bolt means and engaging said recess means to thereby prevent relative turning movement between said first bushing means and said bolt-means.

4. In combination: a hinged cover for an opening of the fire box of boilers, an oil burner arranged on the outside of said cover and provided with a burner pipe extending through said cover, said cover being displaceable in a direction perpendicular to a sealing surface between said opening and said cover, said sealing surface comprising two concentrically arranged sealing rings arranged in spaced relationship with regard to each other so as to define with each other and with said sealing surface a passage closed in itself, blower means, and conduit means extending from said pasage to said blower means to create a certain air pressure in said passage.

References Cited UNITED STATES PATENTS 1,490,281 4/1924 Leach 158-2 3,050,791 8/1962 Trexler 49477 X 3,124,852 3/1964 Holderer 49477 FREDERICK L. MATTESON, JR., Primary Examiner.

E. G. FAVORS, Assistant Examiner. 

1. IN COMBINATION WITH A COVER, ESPECIALLY FURNACE DOOR: A SUPPORTING MEMBER PROVIDED WITH MEANS FOR HINGEDLY CONNECTING SAID SUPPORTING MEMBER TO A FRAME, BOLT MEANS SECURED TO SAID SUPPORTING MEMBER AND HAVING A SUBSTANTIALLY CYLINDRICAL PERIPHERAL SURFACE, SAID COVER HAVING ONE END PORTION THEREOF PROVIDED WITH PASSAGE MEANS OF SUBSTANTIALLY CIRCULAR CROSS SECTION, SAID BOLT MEANS EXTENDING INTO SAID PASSAGE MEANS BUT HAVING A DIAMETER CONSIDERABLY LESS THAN THE DIAMETER OF SAID PASSAGE MEANS SO AS TO CONFINE AN ANNULAR SPACE WITH THE SURFACE OF SAID PASSAGE MEANS, TWO COAXIALLY ARRANGED SLOTTED BUSHINGS ARRANGED WITHIN SAID ANNULAR SPACE AND RESPECTIVELY HAVING THOSE PERIPHERAL WALL SURFACES THEREOF WHICH FACES EACH OTHER PROVIDED WITH SUBSTANTIALLY THE SAME BUT INVERSELY ARRANGED TAPER AND SLIDABLY ENGAGING EACH OTHER 